After AT&T's announcement of its limited data plans I took a closer look at my data usage. I noticed that my iPhone 3GS is sending lots of data on its own in the middle of the night when I'm not even using it. And it's doing so via the 3G network rather than my home wifi which is always turned on. Below is a screen shot of my data usage according to AT&T. Note: On 06/05 at 9:07AM I was still asleep as well (had a late night out). What is going on here?!?